Abstract: An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

Abstract: A system for retaining a folded proprotor blade in flight. The system includes a mounting plate, a first arm coupled to the mounting plate at an acute angle relative to the mounting plate, and a first deformable pad affixed to the first arm and adapted to contact the folded proprotor blade.

Abstract: A system for retaining a folded proprotor blade in flight. The system includes a mounting plate, a first arm coupled to the mounting plate at an acute angle relative to the mounting plate, and a first deformable pad affixed to the first arm and adapted to contact the folded proprotor blade.

Abstract: An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

Abstract: Disclosed is a blade lock assembly, which may include a drag brace coupled to a fold crank assembly and to a rotary wing blade and may further include an actuator assembly configured to be coupled to a rotary wing cuff. The actuator assembly may include an actuator pin housing, an actuation pin at least partially sheathed by the actuator pin housing, and an actuator configured to extend and retract the actuation pin away from and toward the actuator pin housing.

Abstract: An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

Abstract: An exemplary length adjustable link includes a tube having an internal bore and internal surface, a first rod end having a first shaft disposed in a first end of the internal bore, a second rod end having a second shaft disposed in a second end of the internal bore, and a member threadably connecting the first rod end to the second rod end.

Abstract: An exemplary proprotor blade assembly includes a structural skin extending spanwise from a root to a tip and along a chord from leading edge to a trailing edge and a structural core positioned inside of the structural skin, the structural skin comprising hex-shaped structures oriented normal to the structural skin.

Abstract: An exemplary spring-loaded link for an aircraft including a spring interposed between a first and a second rod, the spring, when compressed, urging the first rod and the second rod away from each other.

Abstract: An inboard bearing attachment for carrying centrifugal force (“CF”) loads in a rotor blade assembly of a rotorcraft includes a CF fitting having a curved surface and a shear bearing retainer aligned with the curved surface. A mounting flange connected to either the CF fitting or the shear bearing retainer is used to mount the inboard bearing attachment to a yoke.

Abstract: An exemplary pitch lock for a tiltrotor aircraft to enable and disable a pitching degree of freedom of a rotor blade assembly includes a first tab coupled to a blade stop assembly, the first tab having a first ramp surface, a second tab coupled to a blade cuff, the second tab having a second ramp surface, a hasp having a central opening to receive the first and the second tab and rollers rotatably coupled to the hasp on opposite sides of the central opening, where the rollers engage the first and second ramp surfaces and retain the first and the second tabs in the central opening.

Abstract: An exemplary length adjustable link includes a tube having an internal bore and internal surface, a first rod end having a first shaft disposed in a first end of the internal bore, a second rod end having a second shaft disposed in a second end of the internal bore, and a member threadably connecting the first rod end to the second rod end.

Abstract: An exemplary pitch lock for a tiltrotor aircraft to enable and disable a pitching degree of freedom of a rotor blade assembly includes a first tab coupled to a blade stop assembly, the first tab having a first ramp surface, a second tab coupled to a blade cuff, the second tab having a second ramp surface, a hasp having a central opening to receive the first and the second tab and rollers rotatably coupled to the hasp on opposite sides of the central opening, where the rollers engage the first and second ramp surfaces and retain the first and the second tabs in the central opening.

Abstract: An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

Abstract: An exemplary spring-loaded link for an aircraft including a spring interposed between a first and a second rod, the spring, when compressed, urging the first rod and the second rod away from each other.

Abstract: An exemplary proprotor blade assembly includes a structural skin extending spanwise from a root to a tip and along a chord from leading edge to a trailing edge and a structural core positioned inside of the structural skin, the structural skin comprising hex-shaped structures oriented normal to the structural skin.

Abstract: A rotorcraft rotor blade assembly includes a stub spar extending less than a full span of the rotor blade assembly. An upper skin portion extends substantially the full span of the rotor blade assembly. A lower skin portion extends substantially the full span of the rotor blade assembly. The stub spar is positioned between the upper skin portion and the lower skin portion.

Abstract: A hub system comprises at least one yoke, at least one shear bearing, and at least one mast adapter. The at least one mast adapter is configured to support the at least one yoke and the at least one shear bearing, and the at least one yoke has a flapping hinge that is non-coincident with a flapping hinge of the at least one shear bearing. Another hub system comprises a stacked yoke and a mast adapter. The mast adapter is configured to transfer rotation from a rotor mast to the hub system to rotate the hub system about a central axis of rotation. The mast adapter is further configured to support the stacked yoke such that each yoke in the stacked yoke is configured to accommodate at least some amount of rotation about an axis that is perpendicular to or about perpendicular to the central axis of rotation.

Abstract: A tri-hybrid yoke including a center ring connected to a CF fitting connected to flexure arms. An inboard centrifugal force bearing assembly connects to the CF fitting and a grip. An outboard shear bearing assembly connects to the flexure arm and the grip. In use, the center ring and the CF fittings carry the centrifugal force at a position inboard of the flexure arm.

Abstract: A mechanism for transitioning a tiltrotor aircraft between rotary and non rotary flight modes. The mechanism includes a gimbal lock positioned about a mast that is operable to selectively enable and disable a gimballing degree of freedom of a rotor assembly relative to the mast. A blade stop assembly, positioned about the mast, includes a plurality of arms having a radially contracted orientation and a radially extended orientation. A blade lock assembly is operably associated with each rotor blade assembly. Each blade lock assembly is operable to selectively enable and disable a folding degree of freedom and a pitching degree of freedom of the respective rotor blade assembly. A swash plate is operable to change the pitch of the rotor blade assemblies in the rotary flight mode and fold the rotor blade assemblies in the non rotary flight mode.